Third Grade Weather « Flashcards at Hudson.edu

Front	Back
air pressure	the force exerted by the weight of the atmosphere on a unit area
anemometer	an instrument used to measure the speed of wind
barometer	an instrument used to measure air pressure
cirrus cloud	a wispy or feathery high cloud composed of ice crystals rather than water droplets (fair weather, rain or snow may follow later)
cloud	a mass of very small water droplets
cloud cover	the amount of the sky in which clouds are visible
cobalt paper	specially treated paper used to measure air humidity (blue-low humidity, faint pink/violet- medium humidity, pink-high humidity)
cold front	the leading edge of a cold air mass that forms as the cold air mass moves into a warm air mass (thunderstorms often occur along a cold front)
condensation	the process by which matter changes from gas to liquid
cumulus cloud	a puffy, heaped-up cloud with a flat base, usually accompanied by fair weather
cumulonimbus cloud	often called a thunderhead, brings heavy rain, lightning, and thunder
degrees Celsius	the metric unit of temperature (0 degrees C-freezing, 100 degrees C -boiling)
degrees Fahrenheit	the US Customary unit of temperature (32 degrees F-freezing, 212 degrees F-boiling
dual-scale thermometer	a thermometer that has two temperature scales marked on it
evaporation	the process by which matter changes from liquid to gas
fog	a cloud that touches Earth's surface
freezing	the change of state from a liquid to a solid
humidity	the amount of water vapor in the air at a given temperature and air pressure
melting	the change of state from a solid to a liquid
millibar	the metric unit of air pressure
precipitation	any form of water that falls to the earth from clouds (ex: rain, sleet, hail, snow)
rain gauge	an instrument used to measure the amount of precipitation
stratus cloud	a low, layered cloud usually bringing rain or snow
temperature	a measure of the amount of heat energy in a substance
thermometer	an instument used to measure temperature
tornado watch	the conditions are right for a tornado to form
tornado warning	a tornado has been sighted, take cover
warm front	the leading edge of a warm air mass that forms as the warm air mass moves forward into a cold air mass (light rain often falls along a warm front)
water cycle	the continuous cycle of evaporation, condensation, and precipitation of water in the atmosphere
water vapor	water in its gaseous state
weather patterns	generally move from west to east in the United States
wind	the movement of air over the Earth's surface
wind direction	the direction from which the wind is blowing
wind vane	an instrument used to determine the wind direction